The general aim of this proposal continues to be the study of the relationship between benzene metabolism and benzene toxicity. In this grant period we wish to investigate the covalent binding of benzene to DNA using isolated enzyme and cell systems to produce biological reactive intermediates of benzene and added DNA. We will then compare the adducts formed in these systems with those formed by the administration of benzene in vivo. The adducts formed in vivo will be measured using the "post labeling assay". We also plan to study the effects of benzene on the production of cell growth factors. Thus, we will determine the effects of benzene and its metabolites on the ability of the T-lymphocyte to produce the hematopoietic factors IL-3(multiCSA) and granulocyte/macrophage colony stimulating activity (GM-CSA). We will also determine the effects of benzene on the monocyte-directed production and/or release of hematopoietic factors by the T-lymphocyte.